It was the battle of the Johns this morning on Radio 4. Today's very own inquisitor in chief John Humphrys v John Bolton, onetime US ambassador to the UN and arch defender of the Bush administration.

The testy encounter ended with Bolton saying Humphys' politics belonged to that of the "extreme left wing" and that he was "a superior Brit", at which point Humphrys managed - just - not to lose his cool. What did you make of their exchange and what did it say about UK and US media?

The ostensible reason for the interview was to assess the likely Bush/Brown relationship, but the tone quickly descended when Humphrys asked about a possible invasion of Iran and whether "the biggest power the world has ever seen" has learned nothing from the Iraq debacle. "How many more people need to die?" was Humphrys question. Fair enough, no?

Not for Bolton, he of the bog brush moustache. He had already been on the attack, defending the invasion of Iraq and even accusing Foreign Office mandarins of not listening to government orders. The Brits, he said, were wrong to seek UN support for the Iraq invasion when there was a perfectly good pretext for it without further resolutions.

But we can be sure about one thing: he didn't like Humphrys tone and said that only someone who comes from the "extreme left" could be questioning him like this.

Humphrys responded that he has no views at all. Bolton bounced back by taunting him, asking if his mind was "blank". Back to Humphrys: I don't voice my views on air and you, Mr Bolton, a lawyer, should at least understand what playing devil's advocate means.

And this appeared to hit on the nub of the matter. In the US, print media is pretty neutral while pockets of the broadcast media is fairly partisan - you only have to watch Fox News for three minutes to work that out.

In the UK it is largely the other way round, as Humphrys pointed out. "In the UK we do things differently" he said? Or sneered? Well, Bolton thought so, accusing him of being a "superior Brit".

That's as maybe. But what do you make of their exchange? What does it say about the media and the attitudes to media in the US and UK? And which would you prefer to have?